Multiplying With Fractions Lesson 5-1

Just Follow These Easy Steps! n Multiply the numerators and write down the answer as your new numerator. n Multiply the denominators and write down the answer as your new denominator. n Simplify.

Example x 3 4 = There are no common factors for 15 and 32, so this fraction cannot be simplified.

Example x 2 9 = 6 36 This fraction can be reduced. Divide the numerator and denominator by the GCF, which is 6. = 1 6

Multiplying by a Whole Number If you want to multiply a fraction by a whole number, turn your whole number into a fraction by placing a 1 as the denominator. If your answer is improper, divide the bottom into the top. 4 5 x 20 1 = 80 5 = 16

Another Example 15 x 1 61 = 6 15 and 6 have a GCF of 3. = 5 2 Five halves is improper, so we divide the bottom into the top

Simplifying Factors n Before you multiply, you can make the problem simpler. n You can find the GCF of any numerator and denominator. n Find a factor that equally divides the top number and bottom number, divide, and rewrite the problem.

Example x 8 16 In the second fraction, 8 and 16 have a GCF of 8. 8 ÷ 8 = 1 and 16 ÷ 8 = Now, multiply with the simpler numbers. 5 x 1 = 5 and 7 x 2 =

Example x 5 12 The top of the first fraction and the bottom of the second fraction have a common factor. The GCF of 2 and 12 is 2. 2 ÷ 2 = 1, and 12 ÷ 2 = Now, multiply: 5 18

Multiplying Mixed Numbers 1.Create Improper fractions 2.Multiply numerators 3.Multiply denominators 4.Simplify

Example

Rules of Multiplying Signs for all numbers!!!